package com.devinlee.javautildemo.util;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.Base64;

/**
 * AES对称性加/解密
 * @author devinlee
 *
 */

public class AESUtil {

    private static final Logger LOG = LoggerFactory.getLogger(AESUtil.class);

    public static String key = "devinlee";

    /*
     * 加密 1.构造密钥生成器 2.根据ecnodeRules规则初始化密钥生成器 3.产生密钥 4.创建和初始化密码器 5.内容加密 6.返回字符串
     */
    public static String AESEncode(String encodeRules, String content) {
        try {
            // 1.构造密钥生成器，指定为AES算法,不区分大小写
            KeyGenerator keygen = KeyGenerator.getInstance("AES");
            // 2.根据ecnodeRules规则初始化密钥生成器
            // 生成一个128位的随机源,根据传入的字节数组
            SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
            random.setSeed(encodeRules.getBytes());
            keygen.init(128, random);
            // 3.产生原始对称密钥
            SecretKey original_key = keygen.generateKey();
            // 4.获得原始对称密钥的字节数组
            byte[] raw = original_key.getEncoded();
            // 5.根据字节数组生成AES密钥
            SecretKey key = new SecretKeySpec(raw, "AES");
            // 6.根据指定算法AES自成密码器
            Cipher cipher = Cipher.getInstance("AES");
            // 7.初始化密码器，第一个参数为加密(Encrypt_mode)或者解密解密(Decrypt_mode)操作，第二个参数为使用的KEY
            cipher.init(Cipher.ENCRYPT_MODE, key);
            // 8.获取加密内容的字节数组(这里要设置为utf-8)不然内容中如果有中文和英文混合中文就会解密为乱码
            byte[] byte_encode = content.getBytes("utf-8");
            // 9.根据密码器的初始化方式--加密：将数据加密
            byte[] byte_AES = cipher.doFinal(byte_encode);
            // 10.将加密后的数据转换为字符串

            //String AES_encode = new String(new BASE64Encoder().encode(byte_AES));
            String AES_encode = Base64.getEncoder().encodeToString(byte_AES);
            // 11.将字符串返回
            return AES_encode;
        } catch (NoSuchAlgorithmException e) {
            LOG.error("NoSuchAlgorithmException:", e);
        } catch (NoSuchPaddingException e) {
            LOG.error("NoSuchPaddingException:", e);
        } catch (InvalidKeyException e) {
            LOG.error("InvalidKeyException:", e);
        } catch (IllegalBlockSizeException e) {
            LOG.error("IllegalBlockSizeException:", e);
        } catch (BadPaddingException e) {
            LOG.error("BadPaddingException:", e);
        } catch (UnsupportedEncodingException e) {
            LOG.error("UnsupportedEncodingException:", e);
        }

        return null;
    }

    /*
     * 解密 解密过程： 1.同加密1-4步 2.将加密后的字符串反纺成byte[]数组 3.将加密内容解密
     */
    public static String AESDncode(String encodeRules, String content) {
        try {
            // 1.构造密钥生成器，指定为AES算法,不区分大小写
            KeyGenerator keygen = KeyGenerator.getInstance("AES");
            // 2.根据ecnodeRules规则初始化密钥生成器
            // 生成一个128位的随机源,根据传入的字节数组
            SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
            random.setSeed(encodeRules.getBytes());
            keygen.init(128, random);
            // 3.产生原始对称密钥
            SecretKey original_key = keygen.generateKey();
            // 4.获得原始对称密钥的字节数组
            byte[] raw = original_key.getEncoded();
            // 5.根据字节数组生成AES密钥
            SecretKey key = new SecretKeySpec(raw, "AES");
            // 6.根据指定算法AES自成密码器
            Cipher cipher = Cipher.getInstance("AES");
            // 7.初始化密码器，第一个参数为加密(Encrypt_mode)或者解密(Decrypt_mode)操作，第二个参数为使用的KEY
            cipher.init(Cipher.DECRYPT_MODE, key);
            // 8.将加密并编码后的内容解码成字节数组
            //byte[] byte_content = new BASE64Decoder().decodeBuffer(content);

            byte[] byte_content = Base64.getDecoder().decode(content);
            /*
             * 解密
             */
            byte[] byte_decode = cipher.doFinal(byte_content);
            String AES_decode = new String(byte_decode, "utf-8");
            return AES_decode;
        } catch (NoSuchAlgorithmException e) {
            LOG.error("NoSuchAlgorithmException:", e);
        } catch (NoSuchPaddingException e) {
            LOG.error("NoSuchPaddingException:", e);
        } catch (InvalidKeyException e) {
            LOG.error("InvalidKeyException:", e);
        } catch (IOException e) {
            LOG.error("IOException:", e);
        } catch (IllegalBlockSizeException e) {
            LOG.error("IllegalBlockSizeException:", e);
        } catch (BadPaddingException e) {
            LOG.error("BadPaddingException:", e);
        }

        return null;
    }

    public static void main(String[] args) {
        String source = "blackmamba李忠德devinlee";
        String secret = AESEncode(key, source);
        System.out.println("加密后结果:" + secret);
        System.out.println("解密后结果:" + AESDncode(key, secret));
    }

}
